Abstract: Structural Evolution and Petroleum Geology of the Norwegian Barents Sea

NILSEN, KARE T., PAUL W. GROGAN, GEIR B. LARSSEN

The tectonic development of the Norwegian Barents Sea has provided potential structural hydrocarbon traps in reservoirs associated with rotated fault blocks, compressional anticlines and salt domes. Significant stratigraphic potential also resides in Paleozoic carbonates. Drilling in the Hammerfest Basin has yielded large gas discoveries in rotated fault blocks, but other trapping concepts remain relatively untested. The undrilled area north of 74 degrees, 30 minutes North latitude, currently being mapped by the Norwegian Petroleum Directorate using exclusive seismic, and geological data from boreholes, represents a significant area for future exploration. Prospectivity is critically dependent on the sealing of traps following Neogene uplift of large areas of the Barents Sea platform.

The area is dominated by structural trends inherited from Caledonian and older orogens. Carboniferous rifting established a system of half grabens and intervening highs, followed by late Permian faulting in the west which initiated regional subsidence which continuing into the early Jurassic. Fault reactivation in early Triassic times triggered salt diapirism and provided a structural framework for the evolution of Triassic shelf margins. During the late Jurassic - early Cretaceous, the western basins underwent tectonic subsidence, while the north-eastern platform was subject to gentle compression.

In the late Cretaceous salt was reactivated in the Nordkapp Basin and compressional structures were developed west of the Loppa High. Further subsidence of the western basins was promoted by late Mesozoic and early Tertiary transtensional movements along the North Atlantic rift system. Subsequent regional compression in these basins, and basin inversion in the eastern areas, are of post-Eocene age.

AAPG Search and Discovery Article #90942©1997 AAPG International Conference and Exhibition, Vienna, Austria